Vitamin B6: The Evidence, Food Sources, and Supplement Guidance

Quick answer

Vitamin B6 (pyridoxine) is a water-soluble vitamin that helps enzymes run more than a hundred reactions, including protein metabolism, red blood cell formation, and the making of brain chemicals like serotonin and dopamine. Deficiency is uncommon in people eating a varied diet, and when it happens it is usually linked to certain medications, alcohol dependence, malabsorption, or kidney disease rather than to a simple lack of food. The most important caution runs the other way: very high doses of B6 supplements over time can damage the nerves, causing numbness and tingling, so more is not better. Poultry, fish, potatoes, chickpeas, bananas, and fortified cereals are reliable food sources, and supplements should stay close to recommended amounts unless a clinician directs otherwise.

What vitamin B6 does

Illustration of vitamin B6 foods including poultry, fish, potatoes, chickpeas and bananas beside red blood cell and brain icons — Illustration: vitamin B6 supports protein metabolism, red blood cells and brain signaling, and comes from poultry, fish, potatoes, chickpeas and bananas.

Vitamin B6 is a coenzyme, meaning it helps other enzymes do their work:

Protein metabolism: B6 helps the body break down and use protein from food.
Red blood cells: B6 is needed to make hemoglobin, the protein that carries oxygen in blood.
Brain signaling: B6 is involved in producing serotonin, dopamine, and other neurotransmitters.
Blood sugar and immune support: B6 participates in glucose regulation and normal immune function.
It is water-soluble, so the body does not store large amounts and needs a regular supply from food.

The practical takeaway: B6 is a helper vitamin for hundreds of reactions, and the honest news is that deficiency is usually a medical situation, while the bigger risk is taking too much of it.

What low B6 can look like

Illustration of low vitamin B6 signs including skin rash, sore mouth and tingling hands and feet — Illustration: low vitamin B6 signs include a red scaly rash, a sore mouth, and tingling in the hands and feet.

Low B6 does not have one signature symptom, which is why it is easy to miss:

Skin changes: a red, itchy rash or greasy, scaly patches, especially around the eyes, nose, and mouth.
Mouth and tongue: a sore, smooth, or swollen tongue, and cracks at the corners of the mouth.
Nerves: tingling, numbness, or pain in the hands and feet (peripheral neuropathy) when deficiency is more advanced.
Mood and thinking: irritability, low mood, and confusion have been reported with low B6.
Blood: a form of anemia where red blood cells are small, though this is less common.
The subtlety: because these overlap with many other problems, B6 status is confirmed with a blood test, not guessed from symptoms.

Common causes

Certain medications: some drugs used for tuberculosis, Parkinson’s disease, and epilepsy can lower B6 or increase its loss.
Alcohol dependence: heavy alcohol use is a common contributor to low B6 and other B-vitamin shortages.
Malabsorption: conditions that reduce nutrient absorption, such as celiac disease or Crohn’s disease, can lead to deficiency.
Kidney disease and dialysis: kidney problems change B6 handling, and dialysis can remove the vitamin.
Pregnancy: needs rise in pregnancy, and some women need more than the diet provides.
Older age and poor diet: low intake and reduced absorption can combine in older adults.

None of these means a person has a deficiency. They are the situations where a clinician might check B6 status.

How serious it is

Illustration of vitamin B6 status levels from usually fine to higher risk to medical care — Illustration: vitamin B6 status levels, from a varied diet that is usually fine to higher-risk groups and medical care.

Low B6 exists on a range, and the response should match the level:

Level 1, most people: a varied diet covers B6, and no action is needed.
Level 2, higher risk: if you take one of the medications above, drink heavily, have a malabsorption condition, or are pregnant, ask a clinician whether your B6 should be checked.
Level 3, symptoms: tingling or numbness in the hands and feet, a persistent rash, or a sore tongue in someone at risk is a reason to see a doctor.
The treatment threshold: confirmed deficiency is treated under medical guidance, and the dose and duration matter, because B6 itself can cause nerve problems at high doses.

Vitamin B6 foods

Food is the right source of vitamin B6:

Poultry and meat: chicken, turkey, and beef are strong sources.
Fish: salmon, tuna, and other fish provide B6.
Potatoes and starchy vegetables: potatoes and sweet potatoes contribute well.
Legumes and fruit: chickpeas and other beans, plus bananas, are good plant sources.
Fortified foods: many breakfast cereals are fortified with B6.

The simple rule: a diet with poultry, fish, beans, potatoes, and fruit covers B6 needs easily, and food sources also supply it in balance with other B vitamins.

The neuropathy caution

Vitamin B6 is genuinely important, but high-dose supplements are a real hazard.
Long-term use of large doses (hundreds of milligrams per day) has caused peripheral neuropathy, with numbness, tingling, and unsteady walking that can be slow to improve.
The US tolerable upper limit is 100 mg per day for adults, while the European Food Safety Authority set a lower limit of 12 mg per day in 2023.
Supplements often exceed what food provides, and some “energy” or “nerve support” products stack B6 with other ingredients, so read labels.
The honest position: food first, modest doses if a clinician recommends them, and never treat B6 as a harmless vitamin to take in large amounts.

FAQ

What does vitamin B6 do?

Vitamin B6 helps enzymes involved in protein metabolism, red blood cell and hemoglobin formation, brain chemical production, blood sugar regulation, and immune function. It is water-soluble, so it needs regular intake from food.

What are the symptoms of vitamin B6 deficiency?

Low B6 can cause a red or scaly rash, a sore or swollen tongue, cracks at the corners of the mouth, and, when more advanced, tingling and numbness in the hands and feet. It is confirmed with a blood test.

Who is at risk of low vitamin B6?

People taking certain medications for tuberculosis, Parkinson’s disease, or epilepsy, people with alcohol dependence, people with malabsorption or kidney disease, and some pregnant women are at higher risk. A varied diet is usually enough for everyone else.

What foods are high in vitamin B6?

Poultry, beef, fish such as salmon and tuna, potatoes and sweet potatoes, chickpeas and other beans, bananas, and fortified cereals. A mixed diet covers B6 needs without supplements.

Can too much vitamin B6 be harmful?

Yes. Long-term high doses can cause nerve damage, with numbness and tingling in the hands and feet. The US upper limit is 100 mg per day for adults, and some experts set it lower, so large doses should only come from a clinician.

Sources

National Institutes of Health, Office of Dietary Supplements: Vitamin B6, Health Professional Fact Sheet. https://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/
National Institutes of Health, Office of Dietary Supplements: Vitamin B6, Consumer Fact Sheet. https://ods.od.nih.gov/factsheets/VitaminB6-Consumer/
Harvard T.H. Chan School of Public Health, The Nutrition Source: Vitamin B6. https://nutritionsource.hsph.harvard.edu/vitamin-b6/
Mayo Clinic: Vitamin B-6. https://www.mayoclinic.org/drugs-supplements-vitamin-b6/art-20363468

Disclaimer

This article is for information only and is not medical advice. Always consult a qualified healthcare provider about your health.

Reviewed by the VI Editorial Team. Last reviewed: September 20, 2026